At last after it not being specced on my car and always looking at them and wishing I had one I took the plunge and bought a Flat Bottom wheel and airbag from german ebay off a 2007 TT S-Line. The wheel is identical to the S3 one, apart from the S3 badge at the bottom but thats sorted now with mine from the original wheel on (same size). Everything fits, airbag works, well no warning light on so happy days! Not got the multi function part to work yet as I need to make a wiring loom but not really bothered to be honest as its the look/feel of the wheel I really like. So for all the budding retrofitters with a S3 or A3 who fancy putting a flat bottom wheel in 2007 TT ones fit!!